Tropical Atlantic quiets down

The tropical Atlantic is relatively quiet today, though an area of disturbed weather has developed in the extreme southern Caribbean. This disturbance will move westward over Nicaragua and Costa Rica today, bringing heavy rains of 2-4 inches. The heavy rains that have plagued Honduras, northern Guatemala, and Belize in recent days appear likely to take a break today, although a low pressure area still lingers over the Western Caribbean. The death toll now stands at 44 from two weeks of heavy rains triggered by last week's Tropical Depression Sixteen and this week's tropical disturbance 91L. Hardest hit is Honduras, where 23 are dead and some 193,000 persons have been affected. Approximately 23,000 persons were evacuated of which 19,800 are in shelters. More than 340 houses were destroyed and 4,300 were damaged, with 157 roads damaged or destroyed. The past week's flooding has also killed four in Guatemala, seven in Costa Rica, four in Nicaragua, two in Belize, and four in El Salvador.


Figure 1. Total rainfall amounts over Guatemala have been as high as 16 inches over the northern portion of the country the past week. Image credit: Norman E. Avila, climaya.com.

The forecast
Persistent low pressure and sporadic heavy rains will continue over the Western Caribbean for the next ten days. A strong cold front is expected to push southward into the area next Tuesday, and the tail end of this cold front could serve as the nucleus for a new tropical disturbance that will generate another round of very heavy rains for Honduras, northern Guatemala, and Belize late next week. Wind shear is expected to be in the low to medium range over the Western Caribbean next week (Figure 2), so we will need to be concerned with a possible tropical storm forming by the middle of next week along the old front. High wind shear is expected north of the Caribbean during the coming two weeks, and it is unlikely that any tropical storms will be able to affect the U.S. during the coming two weeks--with the possible exception of South Florida. No computer models are forecasting tropical storm development anywhere in the Atlantic over the next seven days.


Figure 2. Forecast wind shear for Monday night Ocober 27, 2008, at 8 pm EDT, as generated by the GFS model with its 00Z run on Friday October 24, 2008. The shear is shown in meters per second (multiply by two to make a rough conversion to knots). Low wind shear (darker red colors) are expected over the Western Caribbean next week, which may allow tropical storm development. Very high wind shear associated with a southern dip in the jet stream will protect the U.S. against any tropical storms that might develop.

Friday update on the Hurricane Ike portlight.org charity effort
A fully packed 26-foot truck loaded with an estimated $200,000 worth of donated goods dropped much of those supplies off yesterday in Bridge City, Texas. Today, the Portlight truck will head to the Chambers County, Texas distribution center between 9:30 and 11:00 am, and drop off the rest of the supplies. These goods will go to residents on the hard-hit Bolivar Peninsula. You can follow the mission's progress through a newly set-up web site:

http://www.stormjunkie.com/portlight.php

On Saturday, from noon to 3 pm CDT, Portlight will be providing a free meal for 400-500 Bolivar Peninsula residents.

I'll have an update Saturday morning.

Jeff Masters